Abstract/Summary

The composition of air near ground level is not necessarily representative of the troposphere as a whole. In particular in the Antarctic, stratification from the strong inversions often present and scavenging by blowing snow in the lowest part of the boundary layer may lead to air masses aloft being of different composition than those at ground level. The difference in aerosol composition with height in the Antarctic has been shown for the first time with a lightweight sampling system capable of being hoisted to heights of a few hundred meters on a helium-filled blimp. The system was tested at Halley research station in the Weddell Sea region of coastal Antarctica. On more than one occasion, air with a strong sea-salt aerosol component was found aloft, despite the air at ground level showing little marine influence. Meteorological instruments carried on the blimp just prior to one such flight indicated the presence of a strong inversion at the time.